It may be worth trying a compatible stylus in such a case. Usually they have a little sponge thing as the tip. I didn't get on too well with it, but it will be better than nothing. You also might need to grip the stylus quite firmly.
Or lubricate it... I once had a spell using a different type of touchscreen sensor, and while I did want to use a stylus, it was a bit fussy. What worked that time, but wouldn't be suitable generally, was an old felt-tip pin with the felt inside washed clean, then a hole cut in the side of the pen, then soaked in water, so I could rest a finger on the hole and complete a circuit of some kind between the pen and my body.